Biopsych - Exam 1
The resting potential of a neuron is about ___ and during this state there are more ___ ions inside the cell than outside
-70 mV; potassium
While the exact number varies from person to person, the human brain contains approximately ____ neurons
86 billion
When a neuron is at rest, what is primarily responsible for moving potassium ions into the cell?
BOTH the sodium-potassium pump and electrical gradient
Which of the following is the correct sequence of events just prior to, during and just after an action potential?
Resting potential, Stimulation beyond threshold, Depolarization, Hyperpolarization
An ____ axon brings information into a structure, while an ___ axon carries information away from a structure
afferent; efferent
When the neuronal membrane is at rest, the sodium channels ____.
are closed, so there is almost no flow of sodium
Processes that extend from ___ cause endothelial cells lining the blood vessels within the CNS to fuse together tightly, forming the blood brain barrier/
astrocytes
As a general rule, axons convey information ____.
away from their own cell body
Neurons typically have one ____, but many ____.
axon; dendrites
A comparative psychologist ____
compares the behaviors of different species and tries to relate them to their ways of life
The branching fibers off of neurons that get narrower near their ends and whose surface is lined with specialized synaptic receptors are referred to as ____
dendrites
What action tends to open the sodium gates across a neuron's membrane?
depolarization of the membrane
Biological psychologists are primarily interested in the study of the physiological, evolutionary, and _____.
developmental mechanisms of behavior and experience
The two forces that act on the ions that flow in and out of neurons are referred to as ____ and ____ gradients
electrical and concentration
Oligodendrocytes build myelin sheaths in the periphery of the body
false
Research scientists are free to do as they wish when conducting research with animals
false
The blood-brain barrier is made up of closely packed glial cells
false
Oligodendrocytes and Schwann cells are both examples of what type of cell?
glia
Which of the following statements best describes the Refractory Period?
it occurs IMMEDIATELY after an action potential and consists of 2 parts: Ann absolute refractory period followed by a relative refractory period
Tiny cells called ____ act as part of the immune system, removing waste material, viruses and fungi from the brain
microglia
The insulating material that covers many vertebrate axon is called the ____.
myelin sheath
The resting potential is mainly the result of _____.
negatively charged proteins inside the cell
Gaps in the insulating material that surrounds axons are know as ____.
nodes of Ranvier
Myelin is produced by which of the following cells?
oligodendrocytes & Schwann cells
Which of the following describes selective permeability?
only certain molecules are allowed to cross the membrane freely
The membrane of a neuron is composed of ____ with ____ embedded in them
phospholipid molecules; proteins
Small, charged molecules can cross the cell membrane through ____.
protein channels
At the peak of the action potential, the electrical gradient of potassium _____.
pushes potassium out of the cell
An Institutional Animal Care and Use Committee (IACUC) enforces animal research standards and emphasizes "the three R's" which are:
reduction, replacement, and refinement
What term describes the difference in voltage that typically exists between the inside and the outside of a neuron?
resting potential
The action potential of a neuron depends mostly on what movement of ions?
sodium ions entering the cell
Minimalists believe that _____
some animal research is acceptable, but not all
Perception occurs in ____
the brain
When the neuron is at rest, which of the following is partially responsible for keeping potassium ions INSIDE the cell?
the electrical gradient, as a result of HIGH amount of negatively charged proteins in the cell relative to the outsie
The neuron will produce an action potential only if the depolarization exceeds the _____
threshold of excitation
An ontogenetic explanation is one that describes the development of a structure or behavior
true
Dualists argue that some mental phenomena can't be reduced to physical matter
true
Neurons are distinguished from other cells by their shape
true
Neurons receive information and transmit it to other cells
true
Neurons vary enormously in size, shape, and function
true
The all-or- none law refers to the idea that the power and speed of an action potential do not depend on the intensity of the stimulus that started as long as threshold potential has been reached
true
The greater the surface area of a dendrite, the more information it can receive from other neurons
true
The underlying mechanisms of behavior are similar across species
true
